The study provides absolutely no evidence that a mere 30 minutes of tobacco smoke exposure increases the risk of an individual suffering a heart attack. There are many exposures and factors which can cause endothelial dysfunction similar to that observed in the recent study. For example, mental stress has, like secondhand smoke exposure, been found to cause transient endothelial dysfunction (see: Spieker et al. Mental stress induces prolonged endothelial dysfunction via endothelin-A receptors
. Circulation 2002; 105:2817-2820 and Ghiadoni et al. Mental stress induces transient endothelial dysfunction in humans
. Circulation 2000; 102;2473-2478).
The authors of these studies of the effects of mental stress interpreted and reported the results of their studies properly. They explained that their results suggest a mechanism for the observed effects of chronic mental stress on heart disease. For example, Ghiadoni et al. conclude as follows: ‘These findings suggest that brief episodes of mental stress, similar to those encountered in everyday life, may cause transient
(up to 4 hours) endothelial dysfunction in healthy young individuals. This might represent a mechanistic link between mental stress and atherogenesis.’
Note that the authors' conclusion is that brief episodes of mental stress may, if repeated over time, lead to the atherosclerotic process. The authors do not conclude that their study demonstrates that an individual exposed to brief mental stress is at a risk of suffering a heart attack.
It is especially misleading to make an unqualified claim that 30 minutes of secondhand smoke exposure can cause a heart attack in an otherwise healthy person. Unfortunately, many anti-smoking groups are making precisely such a claim.
One such example is the Canadian Lung Association, which claims on its website: "Just 30 minutes' exposure to second-hand smoke hardens your arteries (arteriosclerosis)."
This is obviously not just a misleading statement, but an inaccurate and absurd one. There is no way that 30 minutes of secondhand smoke exposure can cause the arteries to harden. Atherosclerosis is a process which takes more than just 30 minutes. It takes many years.
While the intention of the researchers and groups making these misleading and unsupported statements is to promote the passage of smoking bans, I believe that this exaggeration and distortion of the science is actually going to hurt the cause. There is only so much that the public is going to take. When they realize that anti-smoking groups are actually stating that 30 minutes of secondhand smoke is enough to cause hardening of the arteries, a process that takes many years, the public is going to come to believe that the anti-smoking movement is a joke, or at least that its science leaves a lot to be desired.